Question

Dada a PG (3,9,27,81...) determine o 15º termo.

Answer 1

q=a2/a1=9/3=3

an = a1*q^(n-1)

a15= 3 * 3^(15-1) =3^15 =14.348.907

Answer 2

Q = a₂/a₁
Q = 9/3
Q = 3

$A_{n} = a_{1} . Q^{(n -1)}$
a15 = 3 . 3¹⁴
a15 = 14348907